Data image correlation analysis of the destruction process of 3D printable layered beams subjected to the 3-point bending process

Abstract

Technological processes and materials related to Additive Manufacturing (AM) are gaining popularity in civil engineering 3Dconcrete printing is aimed mainly at the process of rising the inner and outer walls of buildings. In these elements, the main load is axial compression with a low fraction of bending. The 3D-printing process of cement-based materials provides the construction elements with appropriate compressive strength. Although creating elements, which can carry the tensile loading is necessary to make the 3D-printing process used in civil engineering. Therefore, this paper aims to show the response of the 3D-printed cement-based composites to the bending process to find the effect of complex layered structures on their effective properties. Instead of the standard use of an extensometer to obtain Crack Mouth Opening Displacement results, novel Digital Image Correlation measurement technology was used during research. This technology allows for continuous real-time measurements that are extremely difficult when testing brittle materials such as concrete and avoids the additional introduction of external forces caused by the classical measuring device. The proposed AM material contains the interlayer polymeric net and smeared polymeric reinforcement to enhance flexural strength. The use of the polymeric net and smeared reinforcement introduces residual strength into the composite allowing for its further work after brittle phase failure. However, the obtained results showed that analysed layered beams had decreased interlayer resistance. The process of layer cracking occurs subsequently layer by layer and the failure in different layers developed as an independent process including cracks arresting.